Hydraulic brake for railway cars



Nov. 29, 1938. E. E. VAN CLEAVE ET Al. 2,138,263

HYDRAULIC BfiAKE FOR RAILWAY CARS Filed July- 16, 1936 3 Shuts-Shoat 1 va n w aeu A wma T Q v d nn e ,JE my 7 m 1 Al m m L1! Nov. 29, 19 38. E.E. VAN CLEAVE ET AL 2,138,263

HYDRAULIC BRAKE FOR RAILWAY CARS Filed Jul 16, 1956 s Sheets-Sheet 2 a eVr\ m WWW A U mm; mm xi v Nov. 29, 1938. E. E. VAN CLEAVE El AL2,133,263

HYDRAULIC BRAKE FORiAILWAY cans :s sheets-shed -s Filed July 16, 1936 A7IA s W A MW A W W .m WM 5 A Patented Nov. 29, 1938 UNITED STATESPAT-ENTOFFICE 2,138,263 HYDRAULIC ammo ronnsmwsv osns Edwin E. Van Cleave andAlois Wiedenbauen.

Chicago, Ill.

Application July 16, 1936, Serial-No. 90,935-

Claims,

The purposes of the presentinvention are to provide a fluid pump unitsuitable for using oil' in place of gears for transmitting power fromthe handwheel to the mechanical brake applyingmeans. This constructionis designed to occupy approximately the same space, and location, and toutilize the same, attachment means. as are standard with the purelymechanical constructions now generally in use. The new arrangementallows for an improved action particularly with reference to a"partialrelease ofthe brakes without undue physical exertion to maintain therequired pressure ofthe brake shoes on the wheels. This hydraulichandwheel unit is applicable to all classes of railway cars and thepumpthereof may 'be operated either by. a lever or customary handwheel, andfrom this unit to the brakes the mechanical power transmitting means maybe the same as usual without modification thereon Thus the only changerequired "to install the im-' proved operating unit is to substitute'itfor the usual handwheel and reduction" gearing and sheave to which isattached the lift chain by freighticar and shows the location of thepump and ram unit and the customary linkage between .it and the brakerods.'

; Fig. 3 is an enlarged face view partly in section of the pump and ramunit.

Fig. l is a face viewon a reduced scale of the construction shown inFig. 3' but includes a handwheel partly broken away in the place of alever for operating the pump. Fig. 5 is a sectional view of Fig. 3.

' Fig. 6 is a face view partly in section of a modified form of the pumpand ram unit in which intaken on the line 5-5 10 stead of having the oilreservoir wholly surrcund- In order to provide a fluid pressureoperating 20 means for the individual braking systems of rail-- way carsin place of the mechanical units performing the same function, it isdesirable to have means of which power is transmitted to thebrakelevers.

In place of a mechanically operated sheave the new construction has avertically movable oil" pressure operated reciprocating part,-preferably in the form of a yoke-to which a link is attached forconnecting the yoke with the brake mech anism.

tion as above mentioned the new constructionprovides several incidentalfeatures of improve-'. ment such as. a reservoir for oil surroundingthepressure cylinder and plunger," a'rclease valve Aside from the generalpurpose of the inv'en moperating means whichs extends-above the oillevel and a connection between the handwheel and-a pump plunger by meansor which pressure is built up in the pressure cylinder, within whichfits an actuating rain for the brake mechanism.

60 The improved construction with a modification thereof is illustratedin the drawinsain whicha frame structure I therefor with perforated.ears 2 forthe attaching bolts, which perforations are properly spacedto involve no change inthat regard.

The irame'structure I is formed to provide a reservoir 3 for the fluidfor operating the hydrau- '1ic mechanism. This fluid: as is customaryinof the frames ructure i and within which fits a piston or ram Fluidpressure is applied to the bottoniof the piston 5 by means of a pumppiston .8 fitting a pump cylinder I. The intake of the 40 pump cylinder1 is indicated at 8, Fig. 5, and opens on each intake stroke of thepiston-when the spring pressed ball check 9 moves away from "its seat.Upon-the down stroke of the piston,

check Q closes and check l0 opens, permitting the passage of the fluidthrough the passageway --u to the lower endof the cylinder 4, beneathpiston 5. A succession of operating impulses is imparted to the piston'6 by rotating handwheel 12, Fig. 4. Ha-hdwheel ills secured to'aClajlkjFigure l is..an end fragmentary view of a freight car with thepump and'ram unit mounted thereon. a r k gs Fig. 2 is afragmentaryiongitudinal sectiai of a shaft." which is linked to thepiston '6 by the connecting rod H. An optional way of operating piston0', by means of a pump handle. I5, is showninFlg.'3.

The large piston I is shown pivoted at its'upper 5 end at IE to a yokeI! which extends downwardly chanical brakes of the same class fortransmitting motion at right angles from the vertically movable rod l8to the brake levers through a connecting rod and a chain 2|. The pointof attachment 20 of chain 2| to the sheave I9 is further away from thesheave pivot 22 than the pivot 23 connecting the sheave with link |8.Thus a multiplying effect is produced so that slight motions of thepiston 5 are effective for producing a relatively larger motion of link20. To permit a restoring motion of the mechanism above described andrelease or partial release of the brakes a valve 24 is made use of toopen a port 25 affording communication between the lower end of cylinderand the reservoir 3.

In Fig. 5 the valve 24 is shown as a needle valve having threadedengagement with a packing gland '26, but to avoid the use of packing itis preferred to make use of valves of the character illustrated at 28,Fig. 6, which is a slide valve normally held in closed position by aspring 29 and having a port 30 which may be caused to register with thereturn passageway 3| when the valve is depressed by a pivoted arm 32.This-arm is in position to engage the end of the valve stem above itsbearing 33, and above the oil level to minimize the chance of leakage atthe bearing for shaft 34 which carries the arm 32 and passes through thecasing to a weighted handle 35. This handle may be thrown over to theright, Fig. 6, so as to hold valve 28 in its open position, or in caseit is desired merely to release some of the pressure on the brakes,handle 35 is shifted overand returned to only momentarily depress valve28.

The construction illustrated by Figs. 6 and 7 is the same in principleas that illustrated by Figs. 3 and 5, except that in the former case thevalve structure is somewhat modified as explained, and the reservoir forthe operating fluid as indicated at 36 is to one side of the cylinder 31for the pressure responsive piston 38. The power transmitting yoke 39 inthis arrangement may be narrower. The pump cylinder 40 in this case islocated within the reservoir 36 and the pump piston 4| is connected tothe handwheel crank 42 by a connecting rod 43, also within the reservoirand lubricated by the liquid therein. In this case only one check valve44 is made .use of, as the pump cylinder is filled on the upstroke ofthe piston through the apertures 45.

In the use of this supplementary braking means for railway cars thebrakeman as usual stands on ladder 46 and'footrest 41, Fig. 1, and mayoperate the wheel |2 or the lever [5 with one hand only, building uppressure within the cylinder 4 to that required for firmly applyingthebrakes and without feeling considerable back pressure, as with themechanical brakes, and likewise upon releasing the brakes either whollyor only to a limited extent, no undue exertion on the part of thebrakeman is required to resist and hold the. brakes against abackthrust, as it is easy to work the release valve 26 or 24 with one hand.

amazes side of said wall, said frame forming a reservoir and a cylinder,a pump for forcing fluid under pressure from the reservoir to thecylinder, a plunger movable in said cylinder by the fluid pressure,brake-operating means connected with said plunger, a return-flowconnection between said cylinder and reservoir, a valve controllingreturn flow through said connection, and manually adjusted weightedoperating means for con trolling the positioning of said valve either'open or closed. I

2. A hydraulic operating means for the brakes of railway freight carsand for substitution in place of the usual mechanical hand-operatedmeans," comprising a support including an end wall of a freight carand-a frame attached to the outside of said Wall, said frame forming areservoir and a vertical cylinder, a pump for forcing fluid underpressure from the reservoir to the cylinder, said cylinder being closedat its lower end except for a return outlet to the reservoir, a valvecontrolling return flow through said outlet, said valve being locatednear the bottom ofsaid cylinder, operating means for said valveextending upwardly through said reservoir, a plunger .movable in saidcylinder by the fluid pressure, and brake operating means connected withthe upper end of said plunger.

3. A hydraulic operating means for the brakes of railway freight carsand for su stitution in place of the usual hand-operated means,comprising a support including an end wall of a freight car and a frameattached to the outside of said Wall, said frame forminga reservoir anda cylinder, a pump for forcing fluid under pressure from the reservoirto the cylinder, a plunger movable in said cylinder by the fluidpressure, brakeoperating means connected with said plunger and including'a'yoke surrounding said cylinder 'and arranged to transmit thrust fromsaid plunger in the direction of movement of the plunger.

4. A hydraulic operating means for the brakes of railway freight carsand for substitution in place of the usual mechanical hand-operatedmeans, comprising a support including an end wall of a freight car and aframe attached to the outside-of said wall, said frame having thereinhydraulic operating means including coaxial vertically disposed nestedelements, one of which is a ram plunger, another a ram cylinder withwhich the plunger fits, and-another, a reservoir spaced from andsurrounding the ram cylinder, said plimger having a connection at itsupper end for communicating motion ,to brake-rigging, and manuallyoperated means for forcing fluid from cylinder and reservoir, a valvecontrolling return -flow through said connection, and an operatinghandle having means for normally urging said valve either fully openedor fully closed, accordingto. the disposition of said handle to one sideor the other of a medial position.

- 1 EDWIN E. VAN CLEAVE. ALOIS -WIEDENBAUER.

